This invention relates to a cam structure for use in electric and electronic appliances and being capable of varying forces and actions to be applied to a mating object by modifying its cam shape, and more particularly to a connector using such a cam structure.
In the art of mechanical structures, it has long been used to vary a cam shape as a cam mechanism to change the timing of action caused by the cam mechanism. In the art of electric and electronic appliances, however, aside from miniaturization of such appliances, it have not been performed to vary a cam shape for changing the timing.
In general, connectors for use in, for example, mobile phones, charge coupled device (CCD) cameras and the like are much thinner and having contacts arranged in extremely narrow pitches (so-called lighter and more compact connectors). These connectors each mainly comprise a housing, contacts and a pivoting member so that after a flexible printed circuit board has been inserted into the housing, the pivoting member is rotated on a fitting side or opposite side thereto, thereby bringing contact portions of the contacts into contact with the flexible printed circuit board. The housing is provided with a required number of inserting holes for inserting the contacts and also a fitting opening into which the flexible printed circuit board is inserted. The contacts each mainly comprise a contact portion adapted to contact the circuit board, a connection portion to be connected to a substrate or the like, and a fixed portion to be fixed to the housing. The contacts are fixed to the housing by means of press-fitting or the like.
By way of example, described hereafter are Patent Literature 1 (Japanese Patent Application Opened No. 2003-297,489) as an example of a connector of zero-insertion force (ZIF) type, a so-called “back-lock type”, Patent Literature 2 (Japanese Patent Application Opened No. H11-307,198/1999), and Patent Literature 3 (Japanese Patent Application Opened No. 2004-71,160) proposed by the applicant of the present application. Moreover, described as examples of locking structures for a flexible printed circuit board are Patent Literature 4 (Japanese Utility Model Application Opened No. H6-82,783/1994), Patent Literature 5 (Japanese Patent Application No. 2003-422,258) proposed by the applicant of the present application, Patent Literature 6 (Japanese Patent Application No. 2004-307,793), and Patent Literature 7 (Japanese Patent Application No. 2005-178,666).
Patent Literature 1
According to the Abstract of the Japanese Patent Application Opened No. 2003-297,489, the invention has an object to provide a connector having a reduced overall height including an actuator to be operated by a slight actuating force and enabling contacts to move large distances to ensure reliable connection of the contacts. In the disclosed connector, the actuator includes a cam portion and an actuating portion and is formed between the cam portion and the actuating portion with relief grooves into and from which the forward ends of spring portions of the contacts are inserted and removed. The actuator is rotated clockwise about a fulcrum so that the cam portion causes the spring portions and jointing spring portions of the contacts to be elastically deformed to embrace a flexible printed circuit board between projections of contact portions of the contacts, with the result that patterns of the circuit board are connected through terminal portions of the respective contacts to a printed substrate. An insulator includes a ceiling portion for covering the contact portions of the respective contacts and a guide portion formed forwardly of and below the ceiling portion for guiding the flexible printed circuit board being inserted into the connector.
Patent Literature 2
According to the Abstract of the Japanese Patent Application Opened No. H11-307,198 (1999), the invention has an object to provide a connector for a printed circuit board, connecting a plurality of terminals and holding the flexible printed circuit board, which achieves improved operationality and holding performance. The disclosed connector includes a housing having an inserting groove for inserting a flexible printed circuit board or the like, a plurality of contacts arranged side by side so as to permit their contact portions to extend into and retract from the inserting groove, and an actuating member having a plurality of cams and being pivotally movable between a connecting position and a release position. When the actuating member is in the connecting position, operated portions of the contacts are urged by the cams to cause the contact portions to extend into the inserting groove so that the contact portions are pressed against terminals of the flexible printed circuit board or the like, thereby electrically connecting the terminals to the contacts and holding the circuit board or the like. When the actuating member is in the release position, operated portions of some contacts are urged by the cams to cause the contact portions to slightly extend into the inserting groove so that the contact portions abut against the flexible printed circuit board to temporarily hold the circuit board, and the contact portions of the remaining contacts are caused to retract relative to the inserting groove.
Patent Literature 3
According to the Abstract of the Japanese Patent Application Opened No. 2004-71,160, the invention has an object to provide a connector being capable of securely pressing a flexible printed circuit board or flexible flat cable against contact portions of contacts by means of a slider without degrading strengths and specifications of respective components, and being superior in operationality, and achieving narrow pitches of conductors and reduced overall height of the connector. Disclosed is the connector whose contacts each comprise a contact portion, and a connection portion, and further an elastic portion and a fulcrum between the contact portion and the connection portion, and the contact portion, the elastic portion, the fulcrum and the connection portion are arranged substantially in the form of a crank. Further, the contacts are each provided with a pressure receiving portion extending from the elastic portion at a location facing to the connection portion. The slider is provided with urging portions continuously arranged side by side in a row in its longitudinal direction, and is mounted on a housing so as to permit the urging portions to be pivotally moved between the connection portions and pressure receiving portions of the contacts.
Patent Literature 4
According to the Abstract of the Japanese Utility Model Application Opened No. H6-82,783 (1994), the utility model has an object to provide a connector being capable of easily anchoring by pawls of a slider a flexible flat cable even having a rigid reinforcement plate attached to its rear face. Disclosed is a connector construction comprising a housing including contact pins therein and formed with a fitting space into which a flat cable is inserted, and a slider mounted on the housing so that the slider can be detachably inserted into the fitting space of the housing and is pivotally movable outside of the housing upon removal, thereby bringing the flat cable into electrical contact with the contact pins by forcing the slider into the fitting space after the flat cable has been inserted into said fitting space, wherein said slider is provided with on its flat cable abutting surface with anchoring protrusions adapted to be inserted into and anchored in anchoring portions formed in the flexible cables and formed in a reinforcement plate attached to the rear face of the flexible cable.
Patent Literature 5
In Japanese Patent Application No. 2003-422,258 proposed by the applicant of the present application as a construction for locking a flexible printed circuit board, the invention has an object to provide a connector ensuring a required holding force for a flexible printed circuit board, even if the number of conductors is small, without causing any defective connection. According to this invention, the connector to be detachably fitted with a flexible printed circuit board includes a required number of contacts each having a contact portion adapted to contact a flexible printed circuit board, and a housing holding and fixing the contacts therein and having a fitting opening into which the flexible printed circuit board is inserted, wherein the flexible printed circuit board is provided with anchoring portions and a locking member having engaging portions adapted to engage the anchoring portions is mounted on the housing so that the flexible printed circuit board is fixed so as not to be removed from the housing by causing the engaging portions of the locking member to be engaged with the anchoring portions of the printed circuit board, and a further reliable locking can be achieved by providing grooves in positions corresponding to the engaging portions.
Patent Literature 6
In the Abstract of Japanese Patent Application No. 2004-307,793 proposed by the applicant of the present application in order to improve dust-proof property, the invention has an object to provide a connector with high dust-proofing capability and requiring little or no insertion force for a flexible printed circuit board. The connector includes a required number of contacts, a housing, and a pivoting member, wherein the contacts each comprise at least a contact portion, a connection portion, a fulcrum portion, a jointing portion and a pressure receiving portion, and are substantially H-shaped, and when urging portions of the pivoting member are pivotally moved between the connection portions and the pressure receiving portions to bring the contact portions into contact with a connecting object, and wherein the housing comprises a ceiling portion for covering the contact portions of the contacts and an upper wall for covering the pressure receiving portions of the contacts, and the pivoting member comprises an actuating portion, the urging portions, anchoring holes, and a cover portion which covers the tail portions of the contacts after the pivoting member has been pivoted.
Patent Literature 7
According to the Abstract of Japanese Patent Application No. 2005-178,666, proposed by the applicant of the present application for the purpose of improving dust-proofing, the invention has an object to provide a connector improved in dust-proofing and achieving no insertion force for flexible printed circuit board. A connector includes a required number of contacts, a housing, and a pivoting member, wherein the contacts each at least having a contact portion, a connection portion, a fulcrum portion, a jointing portion, and a pressure receiving portion, these portions being arranged substantially in the form of an H-shape, and the pivoting member is so constructed that upon pivotal movement of urging portions of the pivoting member between the connection portions and the pressure receiving portions of the contacts, the contact portions are brought into contact with a connecting object, and wherein the housing has a ceiling portion for covering the contact portions of the contacts and an upper wall for covering the pressure receiving portions of the contacts, and the pivoting member has an actuating portion, urging portions, anchoring holes, and a cover portion so that upon pivotal movement of the pivoting member, gaps between the tip of the upper wall and the actuating portion and between the upper wall and the tip of the pivoting member opposite from the side of the actuating portion of the pivoting member are made as narrow as possible within a range which does not allow the pivotally moving pivoting member to touch the upper wall of the housing.
In the art of the connectors also, constructions have been increasingly used, whose contacts are brought into contact with a connecting object such as a flexible printed circuit board and the like by utilizing a cam structure as in the Patent Structure 1 to 7. In the connectors having the comparatively large numbers of conductors of the Patent Literatures 1 to 7, there are ones having more of eighty conductors. In order to bring more of eighty contacts into contact with a flexible printed circuit board by rotating a cam at a time, a comparatively great force in excess of approximately 90N would be needed. On the other hand, connectors have been miniaturized so that parts to be operated for rotating the cam have also been miniaturized, which makes it impossible to rotate the cam manually.